Pitot Tubes

Pitot tubes are another type of differential pressure flowmeters. They are named after Henri Pitot who came with this invention in the year 1732. Pitot tubes are basically used to detect flow velocity of fluids. Pitot tubes have the potential to measure two pressures at the same time i.e. impact (dynamic) and static. In a Pitot-static tube, the kinetic energy of the flowing fluid is transformed into potential energy for measurement of fluid flow velocity. 




Other Flowmeters

Variable Area Flowmeter

Variable area flowmeters are a type of differential pressure flowmeters. These are simple and versatile devices which are used to measure the flow of liquids, gases, and steam. They work at a fairly constant pressure drop. In these types of flowmeters, a direct visual indication of flow rate is given by the position of the float, piston or vane. The position of their float, piston or vane gets changed as the rising flow rate opens a larger flow area to pass the flowing fluid. When the flow decreases, either the force of gravity or a spring is employed to return the flow element to its quiescent position. Gravity-operated meters also Rotameters must be installed in a vertical position, whereas spring operated meters can be mounted in any position. Each and every variable area flowmeter is available with local indicators. Moreover, they can also be provided with position sensors and transmitters i.e. Pneumatic, electronic, digital, or Fiberoptic types for linking to remote displays or controls. 

Mass Flowmeters

Open Channel Flowmeter

Any conduit or channel in which the fluid or liquid is flowing with a free surface open to the atmosphere is referred to as an “open channel”. For instance, tunnels, nonpressurized sewers, partially filled pipes, canals, streams, and rivers, all these are Open channels. There are various techniques which can be used to monitor an open-channel flow. However, depth-related techniques are the most widespread. These techniques are based on the conjecture that one can instantaneously determine the flow rate of liquid by measuring its depth (or head). Two most commonly used primary devices for measurement of open-channel flows are Weirs and Flumes.


See Mass Flowmeter

Flow Measurement

Flow measurement of liquids is one of the serious needs of modern industrial plants since it is critical to verify the amount of material purchased and sold. Accurate measurement of flow is so much significant in a number of operations, that it can create a whole lot difference between profit making and loss taking. Imprecise flow measurements or inability to take correct measurements can lead to severe results. In addition, flows throughout the process should be maintained near their preferred values with little variability. In such applications, good reproducibility is generally sufficient. Flowing systems require energy, usually provided by pumps and compressors, to create a pressure difference as the driving force, and flow sensors should bring in a small flow resistance, escalating the process energy consumption as slight as possible. Extraordinary considerations are obligatory for concentrated slurries, flow in an open conduit, and other process situations as compared to clean fluids flowing in a pipe.

CAS Data Clients

Make Field Data Available to your windows, SQL and enterprise applications

CAS has developed a number of Data Client products that provide field data to the enterprise applications for purposes of asset tracking, Preventative Maitenance scheduling, Trending, Logging … whatever you application. Now you do not need protocol knowledge / libraries etc to build you applications.

The CAS Data Clients are embedded on ruggedized embedded computers that do not use a fan for cooling. Multiple Ports (serial and Ethernet) are available. Device can also drive a monitor and can be used to local visualization of data. 




CAS2500-03 – ModbusTCP/RTU Data Client

Connects to ModbusTCP or ModbusRTU slaves to read data. The data and transactions are logged. The log files are available and can be transferred to other computers. Current data can be monitored by remote systems running applications that can issue HTTP or SOAP/XMP GET requests - such applications can be easily developed by end users. Of course, this data is available using an Internet Browser such as Internet Explorer or Google Chrome. Connection parameters, device parameters and data parameters are configurable.   

 
CAS2500-04 - BACnetIP Data Client

Connects to BACnet IP devices to read data. The data and transactions are logged. The log files are available and can be transferred to other computers. Current data can be monitored by remote systems running applications that can issue HTTP or SOAP/XMP GET requests - such applications can be easily developed by end users. Of course, this data is available using an Internet Browser such as Internet Explorer or Google Chrome. Connection parameters, device parameters and data parameters are configurable.

DUPLICATE MAC ADDRESSES/DEVICE INSTANCE NUMBERS

What would happen if you had two BACnet MSTP devices with different MAC address but the same BACnet Device ID (Node ID) on the same network and you send a Broadcast Who-is message.
This would be an illegal configuration (no two devices shall have the same Device ID) but the rules for address binding say the last one wins. If new information arrives saying "I-AM Device 7? the old information is replaced.

To understand this answer you must know a thing or two about a token ring networks.
Basically a token ring networks works by passing a token around the network, whoever has the token may send message out, and when they are done with the token they pass it on to the next person in line.

For Example:

• Device A has the MAC address of 0x03
• Device B has the MAC address of 0x04
• Device C has the MAC address of 0x05
• Device A has the token
• Device A responses to any messages it got since the last time it got the token, then sends any custom messages it may have in queue
• Device A sends the token to device B
• Device B has the token
• Device B responses to any messages it got since the last time it got the token, then sends any custom messages it may have in queue
• Device B sends the token to device C
• Device C has the token
• Device C responses to any messages it got since the last time it got the token, then sends any custom messages it may have in queue
• Device C has the token but there is no one with a higher MAC address then Device C so Device C sends it's token to Device A
• Repeat

If you have two different MSTP devices with the same MAC address your network will become unstable and unpredictable results will occur. Both devices will think that they received the token and both devices will attempt to talk at the same time. There will be collisions and you will not be able to determine what device will respond to what poll or what device has the token.

If you have two different MSTP devices with different MAC address and the same Node ID, the device next in line in the token ring will respond first to your requests. This happens because it will be the first device to be passed the token and the first device able to respond. When the token gets passed to the next device ready to respond it will also send a response. any values set by Device A will probably be over written by Device B.

Read more

CAS BACnet Watchdog

"Who changed the set point? Why did that device stop?"

The BACnet protocol does not support authorization or authentication. Use our Watchdog tool to monitor where the commands that changed set points/device states came from. Our tool allows you to monitor some or all devices/objects/properties.

The CAS BACnet Watchdog records MAC addresses, IP address, messages and other information useful in tracking down unauthorized/unexpected commands. It's easy to install and easy to use.